This study will test the immune system response to and safety of two HIV vaccines alone and in combination: ALVAC-HIV (vCP1452) and LIPO-5. ALVAC-HIV (vCP1452) uses a canarypox virus with man-made parts of HIV attached to it. The canarypox virus cannot cause disease in people. LIPO-5 is a mixture of five man-made proteins similar to proteins found in HIV.

These vaccines are not produced from live HIV or from infected cells and do not contain the virus. It is not possible to become infected with HIV from these vaccines.

Detailed Description

Immune priming of cytotoxic T lymphocytes (CTLs) has been most successfully achieved with live attenuated virus or live virus vector vaccines. Recombinant canarypox vaccines have an excellent safety record and have induced HIV neutralizing antibodies and CTLs in early clinical trials. This study will evaluate the use of HIV lipopeptides (LIPO-5) alone and in combination with a canarypox-based HIV vaccine [ALVAC-HIV (vCP1452)] to further increase CTL activity.

Participants in this study will be randomly assigned to one of five groups. Participants in Groups A and B will receive four injections over 6 months. Participants in Group A will receive four injections of either LIPO-5 or a placebo. Participants in Group B will receive four injections of either the ALVAC-HIV (vCP1452) or a placebo. Participants in Groups C, D, and E will receive six injections over 6 months. Participants in these groups will receive either ALVAC-HIV (vCP1452) and LIPO-5 or a placebo. Participants who receive the vaccine combination will receive four injections of the same dose of ALVAC-HIV (vCP1452) and two injections of LIPO-5. The dose of LIPO-5 will be different for participants in Groups C, D, and E.

Participants will have 11 study visits over 18 months; the total duration of the study will be 30 months. The length of visits will vary and may last up to 3 hours. Study visits will include a medical interview, brief physical exam, and blood and urine tests. Participants will be tested for HIV before entering the study and at least five times during the study. All vaccine and placebo injections will be given in the upper arm muscle.

Participants in Groups A will receive four injections over 6 months of either LIPO-5 or a placebo.

Intervention: Biological: LIPO-5

Experimental: B

Participants in Group B will receive four injections over 6 months of either the ALVAC-HIV (vCP1452) or a placebo.

Intervention: Biological: ALVAC-HIV (vCP1452)

Experimental: C

Participants in Groups C will receive six injections over 6 months. Participants in this group will receive either ALVAC-HIV (vCP1452) and LIPO-5 or a placebo. Participants who receive the vaccine combination will receive four injections of the same dose of ALVAC-HIV (vCP1452) and two injections of LIPO-5. The dose of LIPO-5 will be different for participants in Groups C, D, and E.

Interventions:

Biological: ALVAC-HIV (vCP1452)

Biological: LIPO-5

Experimental: D

Participants in Group D will receive six injections over 6 months. Participants in this group will receive either ALVAC-HIV (vCP1452) and LIPO-5 or a placebo. Participants who receive the vaccine combination will receive four injections of the same dose of ALVAC-HIV (vCP1452) and two injections of LIPO-5. The dose of LIPO-5 will be different for participants in Groups C, D, and E.

Interventions:

Biological: ALVAC-HIV (vCP1452)

Biological: LIPO-5

Experimental: E

Participants in Group E will receive six injections over 6 months. Participants in this group will receive either ALVAC-HIV (vCP1452) and LIPO-5 or a placebo. Participants who receive the vaccine combination will receive four injections of the same dose of ALVAC-HIV (vCP1452) and two injections of LIPO-5. The dose of LIPO-5 will be different for participants in Groups C, D, and E.